Mushroom spawn and method of making it



Patented June 23, 1336 UNITED STATES PATENT "OFFICE MUSHROOM SPAWN AND METHOD OF MAKING IT James W. Sinden, State College, Pa., assignor to The Pennsylvania Research Corporation, State College, Pa., a corporation of Pennsylvania No Drawing.

Application September 18. 1935,

Serial No. 41,179

I 6 Claims. (01. 47-11 room. The culture or spawn is carefully grown under incubating conditions and when the mycelium has grown throughout. the substrate. it is then broken up and used to plant the beds for growing mushrooms. For many years the only substrate employed to grow mushroom spawn'was prepared manure from homes. This substrate was diflicult and expensive to prepare and handle and the spawn was often unsatisfactory. As set forth in my United States Patent No. 1,869,517, many of the objectionable features of prior practices are avoided or overcome byemploying a cereal substrate made, for example, from hominy, cracked wheat, whole grain wheat, barley, rye, oats, rice.

5 etc. Other seeds such as clover, bean, pea' or even ground-up corn cobs are included by the term cereal substrate. 4

The present invention comprises an improvement upon the invention covered in my identifled' patentiand is predicated upon my discovery that the speed of growth ofthe spawn is accelerated. the quality improved, and the quantity of growth increased by adding a small amormt of a calcium salt to the cereal substrate.

Ithasbeenproposedtoretainasubstrate neutral-by the addition of alkaliesto a tobacco stem substrate. I have discovered, however, that retaining cereal te neutral is not important in my invention, because alkaline salts of sodium, potassium and mgnesium do not increase the spawn grmzth rate, although they change the acid or base reaction. Moreover, calcium salts, such as calcium chloride, cause improved growth in .ereal substrate while not 5 noticeably changing the alkaline reaction. On the other hand the addition of alkaline salts of. sodium. potassium and magnesium to a tobacco stem substrate produces no greater or less spawn srfiwth than the addition of an alkaline calcium 50 so 'I'hisfact hasled me to believe that tobacco stem substrate and cereal substrate not only re-- act dliferently to spawn growthbut that alkalinity control is not important to accelerate mycelial 55 development in cereal substrate. It is probable that the phosphate metabolism of the fungus rowing in the cereal substrate is afiected, since calcium controls the intake and utilization of phosphate in both plants and animals.

It lsthe general object of my invention to pro- 5 vide an improved method of growing mushroom spawn wherein the time required for growing the spawn is materially reduced, the quantity increased, and the quality improved.

Another object of the invention is to provide an 10 (improved mushroom substrate and a healthy spawn better adapted for rugged mushroo growth and for storage until planted.

The foregoing and other objects of the invention are achieved by adding acalcium salt to a 5 cereal. substrate of the general type disclosed and claimed in my above-identified patent. The calcium salt is added before sterilization of the substrate, and in amounts between about 1 to 3 parts by weight per 100 parts by weight of substrate. 20 Various calcium salts may be used, such as calchloride, calcium nitrate, calcium hydroxidel or calcium carbonate. Preferably, it is advisable to use a calcium salt which is not very s'olub'le'so that most of the salt remains as a 25 reser ve material not involved in the chemical process but available as the dissolved portion is exhausted or combined. Thus the conditions in the substrate are maintained substantially constant over the period of time required to grow the go spawn. with more soluble salts the osmotic concentration maximum for mycelial growth is attained with too low a concentration of the salt which concentration varies as the salt is used.

0! the various calcium salts, calcium carbonate 35 is preferred and while it is alkaline in reaction it is very slightly soluble and in the amounts added it has relatively little eifect on thereaction of the spawn medium. Generally the calcium carbonate as used is in the form of precipitated chalk. 40

After the calcium salt has been added to the substrate the process of sterilization is performed and the substrate is-inoculated and the spawn, Brown as described in detail in my above-mentioned patent and as set forth briefly heretofore.

' The most important eifect of the addition of the 'calcimnsalttotbecerealsubstrateisthevery great increase in rate and amount of mycelial development. Heretofore about twenty-one to twenty-eight days were required to grow the spawn, but by employing the principles of my present invention only about ten to fourteen days are n. This saving is very important commercially as it provides a faster turnover of growin: containers and mahesthe storage of spawn rugged and better able to withstand storage until used.

I have also found that the spawn grown in cereal substrate containing a calcium salt is equivalently drier at the surface of the grains for a given water content than the usual spawn. Therefore the spawn has less tendency to stick together and to a container, and it can more readily be broken up to facilitate planting.

While in accordance with the patent statutes specific examples of my invention have been described in detail, it should be understood that the scope of the invention is not limited thereto or thereby but is defined in the appended claims.

I claim:

1. That method of growing mushroom spawn which comprises preparing a cereal substrate,

adding about 1 to about 3 parts by weight of a slightly soluble calcium salt to the substrate for every100 parts by weight of the substrate, sterilizing the mixture, inoculating the substrate by the introduction of a mushroom culture and incubat- 5 ing until the substrate is overgrown with mycelium.

2. That method of growing mushroom spawn which comprises preparing a cereal substrate, adding-a calcium salt to the substrate, sterilizing the mixture. inoculating the substrate by the introduction of a mushroom culture and incubating until the substrate is overgrown with mycelium.

3. The method of growing mushroom spawn which includes the steps of preparing a cereal substrate, mixing a calcium-bearing material in the substrate and inoculating the substrate with a mushroom mycelium. I

4. Mushroom spawn comprising a myceliuminoculated cereal substrate including about 1 to about 3 parts by weight of a calcium salt to 100 parts by weight of the substrate.

5. A substrate for growing mushroom spawn comprising cereal and a calciumsalt.

6. A substrate for growing mushroom spawn comprising cereal and a relatively small amount of calcium carbonate.

JAMES W. SINDEN. 

